﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace test_6_17
{
    class Call
    {
        public virtual int Add(int a, int b) { return a + b; } 
        public virtual int Sub(int a, int b)
        {
            return a - b;
        }
    }
}
